Existing one-way network systems are rapidly being retrofitted with two-way capability in response to accelerating technological advances in the field of broadband and/or narrowband information services transmission networking. Such networks are hereinafter referred to as "networks", "broadband/narrowband", or "information networks". In addition, new network systems are being installed initially with two-way capability. These and similar systems provide downstream service by carrying programming signals from a network control and/or programming center(s), hereinafter "center" or "control center", to a desired end-user. Such signals include bandwidths that range from approximately 50 megahertz to the upper end of the transmission spectrum, depending upon the media type used. Upstream signals transmitted from the end-user to the center are typically transmitted over the existing telephone network. Similarly, upstream signals that are transmitted over the network and frequency allocation plans currently in use by cable television operators typically use some or all of the frequency range of 5 to 42 megahertz.
FIG. 1 shows a block diagram depiction of a representative bi-directional cable television distribution system currently in use. A center 100, also referred to as the "head-end" of any type information network, transmits signals onto communication links 110. Links 110 feed the transmission to signal splitters 125 which feed a number of end-users 140 through drop lines 130. End-users 140 are located at a "back-end" of such a network. Return signals from end-users 140 to center 100 are generally routed through existing telephone lines.
Video dial tone systems are also evolving in response to rapid technological advances. A video dial-tone system is a type of broadband/narrowband multi-media transmission network system where channels are leased by cable television operators and other information service providers. This type of system merely provides service signal transport and it is anticipated that current frequency allocations will apply. Virtual channels for encoded and/or compressed signals included in these systems will consequently provide a multiplicity of information rates and channel bandwidths.
FIG. 2 shows a block diagram depiction of a representative bi-directional video dial tone network. Such systems add levels of switching 200 and 210 to the broadband network and provide multi-media transmission similar to those systems as described previously. Video dial tone systems furthermore can switch a multiplicity of service providers between a multiplicity of channels.
Broadband/narrowband network communications existent on local, metropolitan, and wide area networks typically rely on communication protocols, such as Token Ring, Ethernet, or Fiber Distributed Digital Interface, to control communications to and from the end-user terminals connected to the network. The interface between the network and the end-user is a network interface module which provides the physical and electrical connection and the proper communication protocol. The use of the network is determined by requiring the end-user to start a session of use by connecting to the network over the public telephone/data network, or through dedicated circuits, and "signing-on". The sign-on is often completed by entering a secured password. "Signing-off" is required at the completion of the session. The sign-on, password, and sign-off information and time are recorded and used to determine usage and other statistical information. No information, other than real time prompts, which facilitates the end-user's access is conveyed from the network controller to the end-user's equipment. Similarly, no information which is based on the end-user's unique selection of services is captured and retained locally within the network and transmitted to the network control center.
Attendant to each of these network systems is the need to provide the end-user with the ability to select from a plurality of services and/or information providers and to properly record those selections for use by the information services provider for customer verification, service billing, and other related purposes. The known manner of providing such a function, however, is industry dependent. By way of example, the cable television industry uses both a services "subscription" and a "pay-per-view" procedure for dissemination and costing the reception of its signals. Single cable systems supply all of the services in the broadband signal spectrum and are presented to the premises of the end-user in the form of a "basic" and a "Premium" service. Dual cable systems commonly provide the basic service on one cable and the premium service on a second cable. In both cases, however, the entire broadband spectrum is being transmitted continually to the end-user's premises.
In either single or dual cable systems, basic services are able to be viewed upon connection to the cable television network for the payment of a basic service charge. The premium services similarly are transmitted on conditioned signals which are not capable of being viewed without a cable television company provided set-top terminal having the capability of unlocking the inverse signal conditioning on the channel(s) carrying the service(s).
Subscription end-users generally pay for specific services on a monthly basis. The billing for this service is based exclusively upon a set of end-user's entries in a billing database at the center. Pay-per-view end-users further call into the center and order a distinct program for a specified time. This process causes an entry into the billing database for that end-user and the pay-per-view charge is entered on the next bill with the subscription charge. The network control center then unlocks the inverse signal conditioning circuits in the set-top terminal on the channel which will carry the conditioned signal. These reverse conditioned channels are then moved from the channel on which they reside in the broadband spectrum and applied to the input of the television set or video cassette recorder on one of a few specific channels, typically channels 3 or 4, which is used to interface the set-top box with the end-user's video cassette recorder or television set.
There are many operational deficiencies with the known system configurations, primarily because of the limitation of currently available access technology. Specifically, the inverse signal conditioning function is available in a number of devices which are readily available in the underground electronics marketplace. The fact that every channel on the broadband spectrum is available at the customer's premises allows the use of such underground electronic devices for the theft of services.
Furthermore, the necessity of applying inverse signal conditioning on a service-by-service basis requires a single input and output port set-top terminal per unit of customer premises equipment if each unit is used to access a different service. Continuing with the cable television case as a consistent example, an end-user who desires to record one premium program while viewing a second premium program necessarily must have two set-top terminals; one for the video cassette recorder and another for the television. Cable service operators only provide one set-top box per end-user, even if more than one premium channel is subscribed. If a second set-top box is desired, the end-user must pay an additional installation charge and an additional monthly charge. Where multiple premium services are being subscribed, the existing network configuration thus creates a bottleneck at the set-top box level which is only designed to be wide enough for one service at a time. An end user can pay for many services but can use only one service at a time.
In addition to creating a bottleneck in the network, the set-top terminal significantly constrains the ability of the end-user to exercise the features inherent in contemporary consumer video electronics, such as picture-in-picture features. Feature rich television sets are thus reduced to simple video monitors operating on either channel 3, 4, or the like when used with set-top technology.
Video dial tone services, mentioned previously, are providing broadband services from a number of competitive multi-media information service providers that are available to many potential end-users. These services further exasperate the current subscription and network use problems. Multiple premium services are now available from multiple vendors. Should video dial tone meet its promise and the Federal Communication Commission's expectations, such vendors will be competing on a service-by-service basis. Each vendor will be required to protect their service from theft and ensure payment for its use. The services will be signal conditioned for protection and each vendor will have its own unique signal conditioning protection. For there to be true competition, however, end-users will be required to have a compliment of set-top boxes for each vendor. This situation creates a multiplicity of installation costs and recurring monthly costs. Absent the end-user absorbing these exaggerated costs, there will therefore be no true competition between such broadband service vendors.
Additional technical, operational, and economic deficiencies to the present cable television and video dial tone networks are existent. Such deficiencies include the elimination of impulse buying of services, the inability to: a. provide directed commercial advertising, b. automatically bill for services used, c. use services without presubscription, d. understand which channels end-users are using, e. to prevent theft of services, and f. provide billable services without an apparatus in the customer's home.
There have been attempts in the prior art at monitoring data network system usage at the customer's premises to aid in building databases typically used for billing the end-user. One monitoring method, utilized specifically in the television industry, identifies a local oscillator signal and its harmonic radiation and/or propagation which thus identifies the particular frequency being used by the end-user. This method and an apparatus to accomplish the same is disclosed in U.S. Pat. No. 4,723,302 to Fulmer et al., which is incorporated herein by reference. The local oscillator signal, however, is a parasitic effect of a television and essentially an undesired result. Consequently, future televisions will eventually eliminate it, thus rendering such methods of detection obsolete and unusable.
Another method of monitoring end-user use at the customer premises includes measuring the flyback voltage variations at the picture tube. Such a system is similarly inefficient.
Each of these devices and methods suffers from the same operational and practical problems discussed previously.
Accordingly, there is a great need for a broadband/narrowband information provision and reception network that allows a multiplicity of end-users to more conveniently and efficiently obtain customer unique access and select at will from a broad range of service and/or information providers. Such a system optimally includes an efficient means for recording those selections for use by the service provider for customer verification, service billing, and other related purposes. There is a further need to provide product commercial information important to specified groups of customers rather than commercials of a generic nature that are arbitrarily disseminated to broad groups. In addition, there is also a need to transform optimized multi-media signals to signals that are useful to end-user's existing equipment.